🔍 Key Concepts

• 46 CFR tank vessel regulations dealing with cargo tank venting and flame screens • The purpose of a flame screen in a tank vent (what it must stop and how fine the mesh must be) • Difference between coarse mesh and fine mesh in terms of stopping flame propagation

💭 Think About

• Think about how small a mesh needs to be to prevent a flame front from passing through vapors in a tank vent – would a very coarse or very fine mesh be more effective? • Compare the mesh sizes in the answer choices: which one represents a significantly tighter (denser) screen suitable for stopping flame travel? • Recall that 46 CFR specifies a minimum mesh size: is that minimum relatively small (coarse) or relatively large (fine) when written as "X by X"?

✅ Before You Answer

• Confirm in 46 CFR that the flame screen requirements for cargo tank vents state a minimum mesh size in wires per linear inch (e.g., “X by X” mesh). • Check which of the listed mesh sizes would be considered fine enough for gas/vapor service rather than just for debris screening. • Verify that the required mesh is described as corrosion resistant wire with at least the specified mesh count, not less.